Secondary Emission Mass Spectrometer (SEMS) consisting of a particle bombardment ionization system (SIMS or FAB) coupled to a tandem quadrupole mass spectrometer has been developed and used to study various aspects of the secondary emission of organics sputtered by primary particles (Ar). On this system we have initiated a systematic study of the energetics of various organic ions in relation to the different experimental parameters which occur in the SIMS and FAB analysis of organics: (i) Primary beam - energy and nature of the primary particles, charge of primary beam, current density, static versus pulsed beam; (ii) Target conditions - type of material, target bias, orientation and conductivity; (iii) Nature of secondary ions - chemical structure, molecular weight, molecular ions, fragments, clusters, cationized molecular ions, etc.; (iv) Charge of secondary particles - positive, negative or neutrals. Some of these experiments have performed this year and reported at the 31st Annual Conference on Mass Spectrometry and Allied Topics (Boston, May 1983). We have analyzed mixtures of various alkaloids and found that MS/MS technique combined with SIMS ionization could be a powerful method for analysis of mixtures of labile biological compounds. Our observation in the difference of the energy distribution of the sample and matrix ions (about 2 eV for m/z 272 of crinine and m/z 277 for glycerol) can be used as a novel method for supressing the interference signal from matrix by positioning and energy analyzer in the front of the quadrupole and preferentially focussing it (energetically) on the ion of interest. Continuation of these experiments will allow us to understand fragmentation and ionization processes of secondary ions under various conditions in SIMS instruments, analyze complex mixtures using particle induced ionization, obtain information on molecular weight and structure of various labile compounds of biological interest and design better conditions for efficient SIMS and FAB experiments.